186 SPEETON SEKIES IN YOBKSHIRE AND LINCOLNSHIRE. [May 1 896. 



point. The marly passage-beds seem to be exactly similar to those 

 which, as Young and Bird remark, exist at the same horizon at 

 Speeton. 1 The section is now entirely hidden, but near a spring 

 which issues from the base of the Red Chalk at the eastern side 

 of Knapton Plantation, less than 200 yards distant from the largest 

 of the old pits, I have found several fragments of belemnites, trampled 

 out of the clayey subsoil by sheep, and these appear all to belong 

 to the stout variety of B. minimus (perhaps = B. subfusiformis of 

 some authors), which abounds in the passage-marls at Speeton. 



A well-boring at East Heslerton, 2 miles farther east, according 

 to the account given in the Geological Survey Memoir, 2 also passed 

 through ' red clay ' immediately below the Chalk, probably denoting 

 the presence of similar passage-marls. 



As will presently be shown, the evidence of the western wold- 

 scarp, both in Yorkshire and in Lincolnshire, is likewise in agree- 

 ment with this interpretation of the Knapton section. 3 



In the more westerly of the Knapton pits, on the slope almost 

 due south of Knapton Hall, the clay seems to have belonged to an 

 horizon altogether lower and not, strictly speaking, referable to 

 any part of the true Speeton Series, a portion of the Kimeridge 

 Clay some little depth below the top being, I think, here 

 represented. I found in one of these old pits a large limestone 

 concretion containing fossils, evidently similar to the septaria 

 referred to by Prof. Judd, 4 which had presumably been rejected 

 when the clay was excavated. This nodule yielded several identi- 

 fiable fragments of ammonites, which I have every confidence in 

 referring to the well-known Kimeridge species Ammonites (Hoplites) 

 eudoxus, d'Orb., a form known, as mentioned on a previous page, 

 to the old collectors as A, evalidus, 5 Bean MS. Phillips also 

 records RJiynclionella inconstans, Sow., from the ' Kimeridge Clay, 

 Knapton' (< Geology of Yorkshire,' 3rd ed. 1875, p. 243). 



There is, therefore, much probability that we have in this clay 

 the equivalent of ' Bed No. 3 ' of Leckenby's Speeton section, and 

 that the horizon is well below the summit of the Kimeridgian strata. 



Owing to the slipped state of the escarpment on these slopes, it is 

 scarcely possible to make any safe estimate of the thickness of the 

 clay between this pit and the base of the Chalk, but it cannot be 

 great ; so that whatever higher beds of the Kimeridge Clay may 



1 • On the Subdivisions of the Speeton Clay,' Quart. Journ. Geol. Soc. 

 vol. xlv. (1889) p. 602. 



2 Mem. Geol. Surv. 1880, ' Oolitic and Cretaceous Bocks south of Scar- 

 borough,' p. 26. 



3 In Heligoland a similar sequence obtains (see Dames, ' Ueber die Gliederung 

 der Flotzformationen Helgolands,' Sitzungsber. k. preuss. Akad." Wissensch. 

 Berlin, vol. 1. 1893, p. 1032), and here also no evidence seems to be forthcoming 

 for the existence of the lowest beds of the Speeton series. 



4 Quart. Journ. Geol. Soc. vol. xxvi. (1870) p. 328. 



5 Prof. Judd mentions the occurrence of this ammonite at Knapton, but 

 considers it (in his later work) as equivalent to A. fascicular is, d'Orb., a 

 Lower Cretaceous species, from which, however, it differs in many respects (see 

 a remark as to this in my former paper, Quart. Journ. Geol. Soc. vol. xlv. 

 1889, p. 613). 



